The impact of the 2011 residency work-hour reforms on patient safety is not known.


To evaluate the association between implementation of the 2011 reforms and patient safety outcomes at a large academic medical center.


Observational study using difference-in-differences estimation strategy to evaluate whether safety outcomes improved among patients discharged from resident and hospitalist (nonresident) services before (2008–2011) and after (2011–2012) residency work-hour changes.


All adult patients discharged from general medicine services from July 2008 through June 2012.


Outcomes evaluated included length of stay, 30-day readmission, intensive care unit (ICU) admission, inpatient mortality, and presence of Maryland Hospital Acquired Conditions. Independent variables included time period (pre- vs postreform), resident versus hospitalist service, patient age at admission, race, gender, and case mix index.


Patients discharged from the resident services in the postreform period had higher likelihood of an ICU stay (5.7% vs 4.5%, difference 1.4%; 95% confidence interval [CI]: 0.5% to 2.2%), and lower likelihood of 30-day readmission (17.2% vs 20.1%, difference 2.8%; 95 % CI: 1.3 to 4.3%) than patients discharged from the resident services in the prereform period. Comparing pre- and postreform periods on the resident and hospitalist services, there were no significant differences in patient safety outcomes.


In the first year after implementation of the 2011 work-hour reforms relative to prior years, we found no change in patient safety outcomes in patients treated by residents compared with patients treated by hospitalists. Further study of the long-term impact of residency work-hour reforms is indicated to ensure improvement in patient safety. Journal of Hospital Medicine 2014;9:347–352. © 2014 Society of Hospital Medicine